1. Field of the Invention
The present invention relates to a core structure of an integral heat-exchanger in which corrugate fins of a first heat-exchanger and corrugate fins of a second heat-exchanger are integrally incorporated with one another.
Hitherto, there has been known, as disclosed in Laid-Open Japanese Patent Application No. 10-231724 or 11-294984, such a core structure of an integral heat-exchanger that corrugate fins of a first heat-exchanger and corrugate fins of a second heat-exchanger are integrally incorporated with one another.
In FIG. 18, there is shown a sectional view of a core structure of an integral heat-exchanger disclosed in the Laid-Open Japanese Patent Application 10-231724. It is to be noted that to assemble the heat-exchanger, a plurality of core structures are piled on one another. In each core structure, first heat-exchanger tubes 1 of a first heat-exchanger and second heat-exchanger tubes 2 of a second heat-exchanger are arranged front and back in two rows in an air-stream direction. The first heat-exchanger is a condenser used to cool a refrigerant that flows in a circuit of an automotive air conditioner, and the second heat-exchanger is a radiator used for cooling an engine cooling water. A corrugated fin (wave-like fin) 3 is arranged between the first heat-exchanger tubes 1 and between the second heat-exchanger tubes 2. That is, the corrugated fin 3 includes a front corrugated part (no numeral) disposed between the first heat-exchanger tubes 1 and a rear corrugated part (no numeral) disposed between the second heat-exchanger tubes 2.
The front and rear corrugated parts of the corrugated fin 3 are integrally incorporated with each other through the intermediary of a connection part 3a. Louvers 3b, 3c are formed in the front and rear corrugated parts of the corrugated fin 3, as shown. Cut-out parts 3d and louvers 3e are formed in the connection part 3a. 
Since the connection part 3a is formed with the cut-out parts 3d and the louvers 3e in this core structure, and the heat transfer through the corrugated fins 3 is obstructed by the cut-out parts 3d and the louvers 3e in the core part of this integral heat-exchanger, it is possible to restrain thermal interference such that heat is transferred, for example, from the higher temperature second heat-exchanger tubes 2 toward the lower temperature first heat-exchanger tubes 1 through the intermediary of the corrugated fins 3.
Referring to FIG. 19, there is shown a core structure of an integral heat-exchanger disclosed in Laid-Open Japanese Patent Application 11-294984. In this core structure, first heat-exchanger tubes 4 of a first heat-exchanger and second heat-exchanger tubes 5 are arranged front and back in two rows in an air stream direction. A corrugated fin (wave-like fin) 6 is arranged between the first heat-exchanger tubes 4 and between the second heat-exchanger tubes 5. That is, the corrugated fin 6 includes a front corrugated part (no numeral) disposed between the first heat-exchanger tubes 4 and a rear corrugated part (no numeral) disposed between the second heat-exchanger tubes 5.
The front and rear corrugated parts of the corrugated fin 6 are integrally incorporated with one another through the intermediary of a connection part 6a. Louvers 6b, 6c are formed in the front and rear corrugated parts of the corrugated fin 6, as shown. Also the connection part 6a is formed therein with louvers 6d. 
In the core structure of this integral heat-exchanger, since the louvers 6d are formed in the connection part 6a, heat transfer through the corrugated fin 6 is obstructed. Accordingly, it is possible to restrain thermal interference such that heat is transferred, for example, from the higher second temperature heat-exchanger tubes 5 toward the lower temperature first heat-exchanger tubes 4 through the corrugated fins 6.
However, in the core structures of the above-mentioned conventional integral heat-exchangers, due to provision of the cut-out parts 3d and louvers 6d in the connection parts 3a, 6a, heat entering into the connection part 3a, 6a is obstructed. Accordingly, a drawback exists in that heat radiation from the connection part 3a, 6a cannot be effectively made.
Further if the louvers 3e, 6d are formed excessively in the connection part 3a, 6a, the air resistance becomes increased and thus makes the air flow poor, resulting in lowered heat-exchanged performance.